CLC5509 Datasheet, PDF (1/11 Pages) National Semiconductor (TI) – Ultra-Low Noise Preamplifier

January 2000
CLC5509
Ultra-Low Noise Preamplifier
General Description
The CLC5509 is a high performance, ultra-low noise pream-
plifier designed for applications requiring unconditional sta-
bility for wide ranges of complex input loads. Both input im-
pedance and gain are externally adjustable, which make it
simple to interface to peizoelectric ultrasound transducers.
The CLC5509 preamplifier’s low 0.58nV
total input
noise makes it ideal for noise sensitive front ends. The high
repeatability in group delay over voltage and temperature
translates into precision edge measurements for Doppler ap-
plications.
The IC consists of an emitter input, common base amplifier
stage followed by a low distortion, closed loop buffer. Exter-
nal negative feedback creates a well controlled input imped-
ance to allow a near noiseless active input transmission line
termination. The preamp is stable against changes in source
impedance of 50 to 200Ω over temperature and supply
variations, with gains from 14dB to 26dB. The CLC5509
preamp architecture is also well suited for use with
magneto-resistive tape or disk drive heads. In these applica-
tions the head bias current can be reused to bias the
preamp. The part is packaged in an 8-pin plastic SOIC, and
runs off ±5V supplies. External biasing is required for the in-
put signal path.
The CLC5509 is constructed using an advanced comple-
mentary bipolar process and National Semiconductor’s
proven high performance architectures.
Features
n 0.58nV total input noise @ 12MHz
n < .5ns group delay repeatability
n High cutoff −3dB @ 33MHz
n Low cutoff −3dB @ 0.5MHz
n 2.0dB noise figure @ 50Ω
n −60dBc intermod for 2V_PP @ 5MHz
n Supply current: 11mA
n Available in 8-pin SOIC
Applications
n Ultrasound preamp
n Tape drive preamp
n Disk drive preamp
Group Delay Repeatability
Connection Diagram
DS101304-1
DS101304-3
Pinout
SOIC
© 2000 National Semiconductor Corporation DS101304
www.national.com